This disclosure relates to toroidal coils used for data collection, communication, or power transmission during drilling of a geological formation.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as an admission of any kind. Identifying the composition of a geological formation can provide information about the likely presence or absence of hydrocarbons in a well. As such, many downhole tools have been developed that attempt to analyze the geological formation from within a wellbore. Electromagnetic logging tools are one type of downhole tool that may be used to measure properties of the geological formation. By measuring the way that electromagnetic signals travel through the geological formation, the composition of the geological formation may be ascertained at various depths through the well.
Traditionally, a pair of toroidal coils may be used as downhole tools to measure properties of the geological formation. The traditional toroidal coils include a dense covering of wire windings to avoid magnetic-flux leakage. However, the large number of windings results in a large impedance mismatch between an outside environment and the toroidal coil. This large impedance mismatch may significantly limit operating characteristics of the toroidal coil (e.g., an operating frequency range). Accordingly, the subject matter of the present disclosure modifies the operating characteristics of toroidal coils.